content: /*
   * Copyright 2010 Aalto University, ComNet
   * Released under GPLv3. See LICENSE.txt for details.
   */
  package interfaces;
  
  import java.util.Collection;
  
  import core.CBRConnection;
  import core.Connection;
  import core.NetworkInterface;
  import core.Settings;
  
  /**
   * A simple Network Interface that provides a constant bit-rate service, where
   * one transmission can be on at a time.
   */
  public class SimpleBroadcastInterface extends NetworkInterface {
  
  	/**
  	 * Reads the interface settings from the Settings file
  	 */
  	public SimpleBroadcastInterface(Settings s)	{
  		super(s);
  	}
  
  	/**
  	 * Copy constructor
  	 * @param ni the copied network interface object
  	 */
  	public SimpleBroadcastInterface(SimpleBroadcastInterface ni) {
  		super(ni);
  	}
  
  	public NetworkInterface replicate()	{
  		return new SimpleBroadcastInterface(this);
  	}
  
  	/**
  	 * Tries to connect this host to another host. The other host must be
  	 * active and within range of this host for the connection to succeed.
  	 * @param anotherInterface The interface to connect to
  	 */
  	public void connect(NetworkInterface anotherInterface) {
  		if (isScanning()
  				&& anotherInterface.getHost().isRadioActive()
  				&& isWithinRange(anotherInterface)
  				&& !isConnected(anotherInterface)
  				&& (this != anotherInterface)) {
  			// new contact within range
  			// connection speed is the lower one of the two speeds
  			int conSpeed = anotherInterface.getTransmitSpeed(this);
  			if (conSpeed > this.transmitSpeed) {
  				conSpeed = this.transmitSpeed;
  			}
  
  			Connection con = new CBRConnection(this.host, this,
  					anotherInterface.getHost(), anotherInterface, conSpeed);
  			connect(con,anotherInterface);
  		}
  	}
  
  	/**
  	 * Updates the state of current connections (i.e. tears down connections
  	 * that are out of range and creates new ones).
  	 */
  	public void update() {
  		if (optimizer == null) {
  			return; /* nothing to do */
  		}
  
  		// First break the old ones
  		optimizer.updateLocation(this);
  		for (int i=0; i<this.connections.size(); ) {
  			Connection con = this.connections.get(i);
  			NetworkInterface anotherInterface = con.getOtherInterface(this);
  
  			// all connections should be up at this stage
  			assert con.isUp() : "Connection " + con + " was down!";
  
  			if (!isWithinRange(anotherInterface)) {
  				disconnect(con,anotherInterface);
  				connections.remove(i);
  			}
  			else {
  				i++;
  			}
  		}
  		// Then find new possible connections
  		Collection<NetworkInterface> interfaces =
  			optimizer.getNearInterfaces(this);
  		for (NetworkInterface i : interfaces) {
  			connect(i);
  		}
  	}
  
  	/**
  	 * Creates a connection to another host. This method does not do any checks
  	 * on whether the other node is in range or active
  	 * @param anotherInterface The interface to create the connection to
  	 */
  	public void createConnection(NetworkInterface anotherInterface) {
  		if (!isConnected(anotherInterface) && (this != anotherInterface)) {
  			// connection speed is the lower one of the two speeds
  			int conSpeed = anotherInterface.getTransmitSpeed(this);
  			if (conSpeed > this.transmitSpeed) {
  				conSpeed = this.transmitSpeed;
  			}
  
  			Connection con = new CBRConnection(this.host, this,
  					anotherInterface.getHost(), anotherInterface, conSpeed);
  			connect(con,anotherInterface);
  		}
  	}
  
  	/**
  	 * Returns a string representation of the object.
  	 * @return a string representation of the object.
  	 */
  	public String toString() {
  		return "SimpleBroadcastInterface " + super.toString();
  	}
  
  }
  